Sample vials are used for collecting multiple specimens of analytes for analysis. For example, on a dairy farm, the milk of each animal may be sampled frequently and the samples sent to a laboratory to analyze them for fat content, impurities, any indications of disease, or other properties. The sample vials are then often discarded, so a large demand exists for inexpensive sample vials.
Certain sample vials commonly used for collecting milk specimens have previously been generally tubular with a round cross-section from bottom to top, a flat or concave bottom allowing the vials to stand up on a flat, level surface, and an integral lid joined to the body by an integral hinge. The sample vials have been carried in racks, resembling a common test tube rack, having wells that each receive a vial but do not latch the vial in place.
One piece liquid-tight vials are discussed in U.S. Pat. Nos. 4,783,056; 4,812,116; RE 37,676; and 6,303,064.